A rattleback (also known as a celt or a wobblestone) is a type of spinning top that will spin in one direction, but when you spin it the other way it will slow down until it stops, wobbling along its length, and will then spin in the opposite direction.

Originally seen as mysterious, they are now regarded as an interesting piece of physics. One of the original papers explaining how they work was presented at the Royal Society in London in 1988.

Bernhard Schoner, a skilled woodworker from Germany, has created another set of wooden rattlebacks for us, made from a different woods. Each one takes several hours to make, and is a beautiful object, as well as having an intriguing mechanism. They vary in length from 21 to 27 cm.

It's a friggin lode stone.Used for navigation by early sea faring cultures like the Vikings. It acts just like a compass needle. Nice find.....but no big mystery. Reading a book once in a while won't hurt you.

The base of the stone is curved in the same way as the blade of a propeller.As the stone rotates, it wobbles on it's shaped base & that translates into rotational energy. That rotational energy is directed through the curved base of the stone which wants to rotate in the direction of the curve like a propeller.

A rattleback (also known as a celt or a wobblestone) is a type of spinning top that will spin in one direction, but when you spin it the other way it will slow down until it stops, wobbling along its length, and will then spin in the opposite direction.

Originally seen as mysterious, they are now regarded as an interesting piece of physics. One of the original papers explaining how they work was presented at the Royal Society in London in 1988.

Bernhard Schoner, a skilled woodworker from Germany, has created another set of wooden rattlebacks for us, made from a different woods. Each one takes several hours to make, and is a beautiful object, as well as having an intriguing mechanism. They vary in length from 21 to 27 cm.

A rattleback (also known as a celt or a wobblestone) is a type of spinning top that will spin in one direction, but when you spin it the other way it will slow down until it stops, wobbling along its length, and will then spin in the opposite direction.

Originally seen as mysterious, they are now regarded as an interesting piece of physics. One of the original papers explaining how they work was presented at the Royal Society in London in 1988.

Bernhard Schoner, a skilled woodworker from Germany, has created another set of wooden rattlebacks for us, made from a different woods. Each one takes several hours to make, and is a beautiful object, as well as having an intriguing mechanism. They vary in length from 21 to 27 cm.